Scrubbing machine

ABSTRACT

A scrubbing machine having a drive unit on which an operator can sit, and a separate scrubbing unit mounted for movement independently of the frame of the drive unit. The scrubber uses double brushes driven under power which will pick up debris from and scrub surfaces on which the unit is operating. The drive unit as shown operates on a dry surface because the scrubbing unit is trailing.

United States Patent Kasper Nov. 14, 1972 [54] SCRUBBING MACHINE1,694,937 12/1928 Floeter ..l5/50 C 72 Inventor: Joseph G. KasperMinneapolis, 1,759,881 5/1930 Bentley ..l5/384 Mirm 2,683,885 7/1954Johnson ..15/50 R 3,197,798 8/1965 Brown et a1. ..15/320 [73] Assignee:Tennant Company, Minneapolis,

Pn'mary Examiner--Edward L. Roberts 22 Filed; S 15 1970 Attorney-Bugger,Peterson, Johnson and Westrnan I A scrubbing machine having a drive uniton which an "IS/A52 operator can Sit, and a separate scrubbing unit I su n e a n s I a v e s u a i a I s a s n I n u I I s s I [58] Field ofSunnis/49 50 the drive unit. The scrubber uses double brushes drivenunder power which will pick up debris from and scrub surfaces on whichthe unit is operating. The [56] References Cted drive unit as shownoperates on a dry surface because UNITED STATES TE S the scrubbing unitis trailing.

1,268,963 6/1918 Gray ..15/50 C X 31 Claim, 22 Drawing Figures PATENTEDNOV 14 I972 3 7 O2 .488

SHEET 1 0r 9 INV-ENTOR; J05PH a. KASPEE Q Z/MW ATTORNEYS PATENTED 1 I97?3, 702,488

sum 2 0F 9 INVENTOR. JOSEPH G. KASPEE P'ATENTEDWMIBYZ 3 702 488 SHEET 3OF 9 M WMW A r TORNEYS PATENTED 14 I972 3,702,488

sum 7 or 9 INVENTOE JOSEPH 6. KflSR SQ fixww w w PATENTED 14 I973 3. 7O2 48 8 sum 8 BF 9 INVENTOI? JOSEPH G. KASPER Q s w/m A r7 0 ENE vsSCRUBBING MACHINE BACKGROUND OF THE INVENTION 1 Field of the InventionThe present invention has relation to self-propelled power drivenscrubbing machines.

2. Prior Art Various types of powered scrubbing machines have beenadvanced in the prior art, and some of them have utilized double brushscrubbing. A typical prior art machine having a double brush handoperated unit is shown in U.S. Pat. No. 3,061,859. US. Pat. No.1,694,937 shows another type of hand propelled floor scrubbing machineutilizing two scrub brushes.

Counterrotating double brushes have been used in street sweepingmachines, for example in U.S. Pat. No. 574,850. In U.S. Pat. No.2,683,885 a double brush floor cleaning machine having an operator seatthereon is shown. This machine is used for picking up liquids or otherdebris from floors and is not utilized with a scrubbing brush.

A further floor cleaner is shown in US. Pat. No. 1,938,068 and this-hasdouble brushes, but the brushes are divided with an axially extendingbaffle which limits their effectiveness.

Many of these prior art devices are very difficult to manufacture, andoperate. For example, there is difficulty in steering or maneuvering thedevices, and when turning the squeegee or drying means utilized willtend to leave streaks or puddles. The devices are not quickly and easilytransported and do not adequately pick up debris. This means that thesurface usually has to be swept before scrubbing in the prior artmachines. Further, the scrubbing job has been incomplete, scrubbingliquid re-use poor, and the ability to get close to walls has been poor.

SUMMARY OF THE INVENTION The present invention relates to aself-propelled scrubbing machine that increases speed of operation,conserves scrubbing liquid and does not require sweeping of the floorbefore scrubbing because of the ability to pick up debris. The drive andsteering wheels are on a power unit of the vehicle, and a double brushwet scrubbing assembly forms a separate unit. The two units areconnected together with links to permit the unit carrying the scrubbingbrushes to be raised and lowered with respect to the power unit. Acontrolled floating action on the scrubbing unit is provided to controldown pressure on the scrubbing brushes.

The entire assembly is constructed so that the components utilized arearranged for balance, and the double brushes used with the scrubbingunit are properly positioned and of proper construction and size, andoperated at proper speed to pick up debris as well as scrub. The unitmay be thus used as a dry sweeper. The water or scrubbing liquid isreused by carrying it over the leading one of the brushes, and anyexcess water or scrubbing liquid carried by the trailing brush issqueegeed up and carried to a tank with a vacuum. A debris hopper orreceptacle is provided to receive debris and water or scrubbing liquidswept up by the scrubbing brushes. The debris hopper may be mountedahead of the double brush unit, or to the rear of the double brush unit,as desired.

As shown, the two brushes are mounted so that they will scrub close tothe side edges of the machine, and the brushes are made so that they canbe removed for service by removing a bracket at one end of the brushes,and being pulled in this direction.

The frame member for the trailing unit includes a divider and guidebetween the brushes so that scrubbing liquid will be recirculated andreused, and debris will be guided into the debris receptacle.

Additional features include optional short turn devices for the driveunit and a sensing device to automatically remove some of the downwardload on the brushes when the power required to drive the brushesincreases, thereby providing automatic compensation so that the engineused with the unit is not overloaded.

If desired, the trailing unit can be mounted to move sideways so thatsharper turns may be made when the unit is adjacent the wall, andpositioning of the hydraulic reservoir used for supplying fluid to thefluid actuated drive components at the forward end of the drive andpower unit to counterbalance the trailing unit.

Two difierent size brushes may be used in the double brush scrubber forobtaining the desired control of the scrubbing operation.

A feature of the invention is that the power unit operates on a surfacethat has not been wetted by the scrubber. In instances where the entiresurface has been flooded or is wet from external sources prior toscrubbing, the device may include means to deliver a drying air blast tothe wet surface immediately ahead of the drive and steering wheels.

The side squeegees used are mounted with leaf springs to permit them tofloat and still prevent escape of wash water and debris, even whenturning. The side squeegee leaf springs also automatically adjust forwear of the cylindrical brushes, so they don't have to be manually resetor adjusted. The rear squeegee cooperates with the side squeegees toprevent streaking in turning. A hydraulic cylinder controls up and downmovement of the rear squeegee so that it can be lifted upwardly whendesired to prevent damage, or forced downwardly with the desired amountof force.

The scrubber has variable speeds, is easy to steer and control, and ishighly versatile.

Objects of the invention are to provide a versatile scrubbing machinewhich has long life, good reuse of the scrubbing liquid, picks up debrisas it scrubs, variable speed, has ability to lift and lower thescrubbing unit, and provides the features described above and in thefollowing specification.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of ascrubbing machine made according to the present invention;

FIG. 2 is an enlarged side elevational view of the device of FIG. 1 withparts in section and parts broken away;

FIG. 3 is a fragmentary enlarged top plan view of a scrubbing unit ofthe present inventiontaken as on line 3-3 in FIG. 2;

FIG. 3A is a fragmentary perspective view showing a debris hopper beingremoved from the scrubbing unit of the present invention;

FIG. 3B is a fragmentary sectional view taken as on line 38-38 in FIG.3;

FIG. 4 is a side elevational view of the scrubbing unit with parts insection, and controls for a rear squeegee used shown partlyschematically;

FIG. 5 is a fragmentary side view of a side squeegee showing the leafspring mounting thereof;

FIG. 5A is a fragmentary sectional view taken as on line SA-SA in FIG.5.

FIG. 6 is a schematic representation of thehydraulic circuit for thedevice of the present invention;

FIG. 6A is a schematic representation of a modification of the drivecircuit to aid in making sharper turns;

FIG. 7 is a part schematic side view of the trailing unit of the presentinvention showing a control for relieving the downward pressure on thescrubbing brushes in response to the torque required to drive thebrushes;

FIG. 8 is a fragmentary side sectional view showing a hopper dumpmechanism made according to the present invention;

FIG. 9 is a top plan view of the device of FIG. 8;

FIGS. 9A and 9B are a side and a top view respectively, of a manualactuator for the hopper dump mechanism;

FIG. 10 is a schematic top plan view of a modified form of the inventionshowing a traversing trailer scrubber unit which permits sharper turnswhen the scrubber is adjacent to a wall;

FIG. 10A is a fragmentary rear view taken on line l0A-l0A in FIG. 10;

FIG. 1 1 is a side view of a modified scrubber showing means for dryinga surface that was wet prior to scrubbing;

FIG. 12 is a detailed view of a selector valve used when exhaust gasesare used for the drying air blast;

FIG. 13 is a view taken as on line 13-13 in FIG. 11;

FIG. 14 is a side view of a scrubbing unit modified to mount the maindebris hopper ahead of the brushes and also showing a second rearmounted hopper; and

FIG. 15 is a side view of a scrubbing unit showing brushes of differentsizes used for scrubbing.

A scrubbing machine illustrated generally at 10 made up of a power anddriving unit 11, and a scrubbing unit 12, which are independentlyconstructed, and are connected together so that the power unit 11 will,as shown, pull the scrubbing unit 12 over the surface to be scrubbedthrough a plurality of connecting links illustrated generally at 13. Thepower unit comprises a main frame 14, powered drive wheels 15 at therear thereof, and a front central steering wheel 16. This perhaps can bebest seen in FIG. 6A. Each of the drive wheels 15 is driven through aseparate hydraulic motor 17 and 18, respectively, which are powered in asuitable manner through a variable volume pump, as desired. Thehydraulic motors are thus variable speed controlled, and a foot pedal 21is used for controlling the speed of the vehicle by adjusting thevariable volume pump.

The scrubbing drive unit can have brakes operated from a pedal 22 by anoperator sitting on the operator seat 23. The hydraulic motors l7 and 18can be mounted to the frameof the power unit independently, and thedrive wheels 15 are then drivably mounted on the respective outputshafts of the drive motors. Any other suitable arrangement can beutilized for driving the vehicle in well known manner.

The steering wheel .16 is. mounted about'an upright axis with a suitableframe 24, and is controlled from the operator steering wheel 25 througha drag link 26 and steering arm 27 shown in FIG. 6A. An automotive typesteering gear is used at the base end of the steering column.

The drive unit is powered with an air cooled engine illustratedgenerally at 30 located at the forward end of the power unit 11 andmounted onto the frame 14. The air cooled engine as shown is used forthe components, such as a main drive'variable volume pump 29 (shown onlyschematically) and a hydraulic pump 31 for accessories, driven through abelt arrangement 32 from the engine output shaft. The pump 31 is usedfor powering the hydraulically driven components of the unit. As can beseen, a main hydraulic fluid reservoir 33 is at the front part of theframe 14.

The frame for the power unit also supports a clean scrubbing liquid tank34 on which the operator seat 23 is mounted, and as can be seen theclean liquid tank is hingedly attached to the frame so that it can betilted rearwardly as shown in dotted lines in FIG. 2 to permit access tocomponents positioned under the clean liquid tank. The battery, filterand other components can be housed under the clean liquid tank. Theclean scrubbing liquid tank is used for supplying water or otherscrubbing liquid, such as detergent or solvent solutions, to the surface35 over which the vehicle is moving and which will be scrubbed.'Thismeans that there will be wet scrubbing. As shown, a hose 36 extends fromthe cleanliquid tank downwardly to a transverse scrub liquid spreaderpipe 37 which extends across the width of the machine and-is spacedslightly above the surface, and permits the scrubbing liquid indicatedat 38 to run out onto the floor and wet the surface ahead of thescrubbing unit 12. The pipe 37 of course may be of suitable type ofapplicator pipe, and these per se are well known in the art. The pipe 37comprises a liquid distribution header. The tube 36 includes a manuallyoperated on-off valve to control liquid flow. Clean liquid can besupplied to the liquid spreader pipe or nozzles under pressure orgravity feed.

The scrubbing unit l2,'as shown, has a frame-indicated generally at 41surrounding the scrubbing unit. This frame 41 is in turn reinforced witha cover frame plate 42 fixed thereto, and a transverse support anddivider baffle member 43 fixed to the plate to reinforce the plate (FIG.4). The frame 41, as shown, has a removable brace member 44 on one sidethereof removably joining front and rear cross members, and

this brace member may be removed (see FIGS. 3 and 4) to permitinstallation and removal of a pair of scrubbing brushes 45 and 46. Theforward or leading scrubbing brush 45 is driven so that it rotates indirection as indicated by the arrow 47, and the rear or trailingscrubbing brush 46 is driven as indicated by the arrow 48. The brushesare selected to have good debris pick up characteristics. Thus the rowsof bristles are spaced to permit the brushes to walk over debris. Thebrushes are not full fill brushes. Further, the bristle rows arepreferably of a herring bone pattern.

On the opposite end of the brushes from the removable brace, the drivemotors for the brushes are shown. These motors are fixed displacementhydraulic motors 51 and 52, respectively. The hydraulic motors arefastened through brackets 53 to the side of the frame 41 and the motorsextend inwardly so that the output shafts of each of the motors, forexample the drive shaft 52A shown for motor 52 is coaxial with therotational axis of its respective brush. As shown, the brushes areconstructed with an open tubular core member, as shown at 513 and 52B,and the bristles extend outwardly. The hydraulic motors fit within therespective tubular members. The shafts for the hydraulic motors havesuitable connections for connecting to mating adapter plugs shown at 56,in each of the respective brushes. The drive connections from thehydraulic motors are through the adapter plugs to the interior of thetubular members 51B and 52B. The brushes are both supported by-theirrespective motor shafts 52A and 51A, and also are driven by theseshafts.

The opposite end of the brushes are mounted on idler bearing plugassemblies attached to the brace member 44 which, as shown, fixedlymounts a pair of shafts 57 and 58, respectively. The shafts may bewelded to the brace member, if desired. These shafts 57 and 58 in turnhave suitably mounted bearings thereon which are merely idler bearings,and brush end adapter plugs 59 and 60, respectively, are mounted ontothe bearings so that the plugs will rotate freely with respect to theseshafts. The adapter plugs fit inside the tubular cores for the brushesand in turn have flanges which abut against the end surfaces of thetubular cores for the respective brushes 45 and 46. The plugs fit snuglywithin the interior cores. Thus when the brace member 44 is bolted inplace the frame 41 is held together, and the plugs 59 and 60 fit insidethe brushes to hold them in proper position relative to the frame and tothe drive motors. The brushes will rotate under power when theirrespective hydraulic motors 51 and 52 are powered. The brushes 45 and 46may be rotated at the same speed, or at different speeds. The higherspeed brush, if different speeds are used, is the one adjacent thehopper. Different speeds on the brushes may help in debris pick up(sweeping action) as well as liquid pick up. As an example of preferredoperation, brushes having an outer diameter of 11 1s inches are operatedat between 450 and 550 rpm. with both brushes at the same speed.

A door 61 is provided to cover the opening through which the brushes areremoved and serviced. A suitable hinge 62 is provided for this door.

The divider baffle 43 is a transverse member, as shown, and ispositioned above the two brushes 45 and 46.

In this form of the invention, as shown, a debris hopper illustratedgenerally at 65 is mounted. As shown, in FIGS. 3A and 3B, the debrishopper 65 is removably supported on provided ledges 41A formed by theframe 41, and has a lip portion 67 which is closely adjacent thebristles of the rear brush 46. The lip also is substantially along orslightly below a horizontal plane passing through the rotational axis ofthis brush. The frame plate member 42, as shown, ends along a rearwardedge that overlies the debris hopper, so any liquid thrown up by thebrushes and carried along the underside of the panel will drop off intothe debris hopper.

The debris hopper has a pair of handles 68 that can be used for manuallyremoving the hopper from the frame member for emptying when the hopperis full of debris.

Then, at the rear of the frame 14, and inside the frame, there is a rearsqueegee assembly illustrated generally at 70 which is controlled in upand down direction with a hydraulic cylinder 71 (FIG. 4) operatedthrough a valve of suitable design, as explained in connection with FIG.6. This squeegee assembly 70 is mounted on pivoting parallel arms 72,72on opposite ends thereof so that when the unit is raised and loweredwith the hydraulic cylinder 71, it will raise parallel. Also as it wearsand is lowered, the squeegee will move straight down against the surfacerather than cock at an angle thereto. The squeegee has a top frame 73with upright members 73A to which the links 72 are pivotally mounted.The opposite ends of the links 72 are pivoted to the frame member 41.

The hydraulic cylinder 71 can be used to provide a down force on thesqueegee, and when the down force is overcome (a relief valve in valve71A is used for relieving this force) the squeegee will raise guided bythe parallel arms 72 against the down force of the relief valve.

As shown, the rear squeegee top frame member 73 has resilient,downwardly extending, spaced apart flaps 74 attached to frame 73. Theflaps can be made of a suitable elastomeric or other flexible materialthat will give slightly and provide a good drying seal against thesurface 35 to trap any liquid that gets past the scrubbing brushes andcollect it. The forward flap has a rib 74A that will engage the rearflap when the flaps are under vacuum to prevent the vacuum from beingclosed off from the ends of the squeegee. The flap has slots so liquidcan go between the flaps. The double brush assembly actually picks upmost of the scrubbing liquid in the hopper, and the rear squeegee insome instances can be lifted off the surface.

A vacuum fan illustrated schematically at 75 is mounted on the vehicleframe in a suitable location, and is driven with a hydraulic motor 75A.The suction line, shown schematically, is connected to a dirty liquidtank illustrated schematically at 76 also mounted on the frame below theoperators platform. This tank is closed and sealed with a plenum chamberat the top. The plenum chamber has a vacuum line 77 leading therefrom onthe output side. Line 77 is above the liquid level. The vacuum hose 77extends from the power and drive unit where the dirty liquid tank ismounted, back to the scrubbing unit, underneath the frame plate member42. The end of vacuum hose 77 has a Y connected pipe assembly 78thereon. The Y pipe coming from the vacuum hose 77 is split and has twovertical sections 78A and 78B. Section 78A fits down inside the debrisreceptacle or hopper 75. The vacuum pipe 78A just clears the floor ofthe receptacle by a short distance and is surrounded by a screen 79(large size) that keeps out large pieces of debris, as shown in FIG. 38.

Pipe 78B extends downwardly through a provided recess in the debrisreceptacle or hopper 75, and is removably coupled with a slip coupling78!) to a fixed pipe 78C which has a tapered end portion. The lower endof fixed pipe 78C fits between the rear flaps 74 to create a vacuum orsuction on the channel formed between the squeegee blade members. Thesqueegee flaps extend around the rear of the machine and then extendforwardly adjacent the sides of the machine to guide liquid toward thecenter of the machine. Thus the rear squeegee members collect the liquidfrom surface 35 that is left over from scrubbing. The liquid movestoward the rear center of the squeegee, enters the chamber between thefront and rear squeegee members, and then is vacuumed up through thepipe 78C, 783 and into the Y portion 78, tube 77 and back to the dirtyliquid tank. The liquid is collected in the dirty liquid tank. Likewise,any liquid that is carried into the receptacle or hopper 65 by the brush46 will be vacuumed up or sucked up through pipe 78A. A screen or grilleprotecting member is provided adjacent pipe 78A if desired to preventdebris from being picked up by the vacuum pipe 78A. The rib 74A preventsthe front flap 74 from collapsing and cutting off vacuum from the endsof the squeegee.

In addition to the rear squeegee assembly, there are squeegees providedalong the sides of the scrubbing unit. As shown in FIG 3, There is asqueegee assembly 80 along the right hand side of the unit which isfastened to the frame member 41, and a squeegee 82 which is along theleft hand side of the unit and this squeegee is fastened to the covermember 60 so that it moves with the cover member. Both the squeegees 80and 81 are provided with end portions 80A and 81A, as shown in FIG. 3,that go on the inside or forward edge of the forwardly extending endportions of the rear squeegee 70. The scrubbing liquid collected alongthe side squeegees is thus guided to the rear squeegee and furtherguided toward the center thereof for pick up.

The squeegees are mounted a unique manner, as shown in FIG. 5. The sidesqueegees each comprise upper frames 82 and they are mounted on leafsprings 83 which are attached to the frames 82, and to some portion ofthe main frame 41. In the case of squeegee 81, it is attached to thedoor 61. The leaf springs permit the flexible skirt portion 84 of thesqueegee which is attached to the frames 82 to move laterally over thefloor and to give slightly sideways, and also move up and down in alinear direction without causing the squeegee to twist, rub extensivelyand wear out.

The leaf springs further provide some give when the unit swings sidewaysduring turning, as a trailing unit will, and provide for automaticadjustment for wear of the brushes. The leaf or blade springs give tocompensate for this wear without manual adjustment.

Small brushes 85 are attached to the frames 82 and are positioned alongside the main brushes and are row brushes. The side squeegee members areformed so that the flexible sections 84 extend outwardly at an anglewith respect to the support 82. The flexible sections extend outwardly,as shown in FIG. A, and the brushes 85, which are attached to the upperframe 82, extend inwardly toward the main rotary brushes 45 and 46. Thesmall brushes 85 are positioned to engage the surface being swept, aswell as being very close to the end bristles of the main rotary brushes45 and 46. This action keeps the debris from being spilled out aroundthe ends of the main brushes and also prevents the debris from beinglost from between the brushes 45 and 46 underneath the squeegees whenthe corners are being turned and the rotary brushes slide sideways.

The outwardly extending flexible sections on the squeegee will insurethat the side portions are kept free of debris and also the scrubbingliquid is kept inside the unit. The outward extension of the flexiblesection makes it easier for the flexible sections 84 to be in contactwith the surface 35 where the flexible members on the side squeegeesangle inwardly to be inside the rear squeegee as shown in A and 81A.This outwardly extending slant of the flexible section also permits themto follow the surface 35 when comers are being turned without turningunder and getting out of position. When the vehicle is turned thesqueegees have to slide sideways a substantial amount. The straightflexible members tend to fold in or out and when this happens, thesqueegees would fold out of position and no longer give a good seal. Theoutward slant of flexible members prevents this.

The scrubbing unit is attached to the power unit in an independentmanner. While rear mounting is shown, the unit may be front mounted andpushed rather than pulled. The improvements described in the scrubbingunit are very beneficial whether the unit is front or rear mounted, butrear mounting permits the power unit 1 1 to operate on a dry surface.The links shown generally at 13 are shown in greater detail in FIGS. 2,3 and 4. As can be seen, a pair of spaced apart channel members 87 arefixed to the top plate member 42 of the frame 41 and extend upwardlytherefrom to form a control mast assembly. It should be noted that thesechannel members are positioned substantially directly above the crossframe member 43 that extends transversely across the frame.

The channel members 87 in turn have. a channel shaped main tow and liftlink 88 pivotally between them with a pin 89. The pin 89 extends along atransverse axis. The link 88 as shown, is not straight, but has a bendin it for clearance purposes, and the opposite end of the link 88 ispivotally attached with a pin 90 to a provided mounting portion of theframe 14 of the power unit. In addition, the scrubbing unit is connectedto the power unit with a pair of spaced'apart outboard drag links 91 and92, respectively, which have suitable part spherical seat pivoting rodends thereon. First ends of the drag links are attached to suitable ears93 on the main frame of the power unit 11, and the opposite ends oflinks 91 and 92 are attached to suitable ears 94 on the frame platemember 42 of the scrubbing unit. These drag links keep the scrubbingunit properly positioned as it is being towed through the main pull link88, and also control the angle of the scrubbing unit with respect to thesurface 35 as the scrubbing unit is raised.

The support for the scrubbing unit comes through link 88, and this linkcan twist and give to permit one end of the scrubbing unit to raiserelative to the other as it moves over irregularities. The links 91 and92 permit this movement.

Raising and lowering of the scrubbing unit is controlled with ahydraulic cylinder 95, which can be single acting because it only has tolift the scrubbing unit, and the weight of the scrubbing unit will causeit to retract, and this hydraulic cylinder 95 is attached as at 96 tothe main frame of the power unit. The cylinder 95 9 has an extendableand retractable rod 97 pivotally attached as at 98 to the link 88.

Thus, when the power unit is powered and moving over the surface, thelink 88 will pull the scrubbing unit along, and the links 91 and 92 willalso keep the scrubbing unit properly positioned and exert a pull onit,'while permitting the unit to float over objects, if necessary.

As can be seen in FIG. 2 in dotted lines, the trailing unit can beraised. The drag links 91 and 92 control the angle of the scrubbing unitwith respect to the surface when the scrubbing unit is lifted. When thepull link 88 is raised to its dotted line position, it can be seen thatthe rear portions of the scrubbing unit raise much higher than theforward portions to provide for clearance at the rear if the vehicle isdriven up an inclined surface.

A safety lock member 100 is pivotally mounted about the same pin 98 asthe rod of the hydraulic cylinder, between the legs of the link 88, andis controlled through a push pull control wire 101 which is similar toan ordinary choke control. The control wire can be moved to its solidline position as shown in FIG. 2, and then the cylinder 95 will beoperable and can be retracted when the control valve for the cylinder isoperated. However, when the cylinder 95 is extended, the control 101 canbe pushed to its dotted line position by an operator and this will movethe safety lock member 100 into position as shown in dotted lines wherethe end of the member 100 will abut against the end surface of thecylinder itself around the rod, and prevent the rod from retracting.This will hold the scrubber unit raised even if hydraulic pressureshould fail, as a safety measure. The scrubbing unit is raised and maybe locked in raised position for rapid transport without having thebrushes and squeegees wearing against the surface 35.

The control line leading to the cylinder 95 can have a suitable valveassembly shown schematically at 102, which can be adjusted so that onlya desired amount of lift pressure will be exerted on the cylinder 95.This will mean that the operator can vary the load supported by thecylinder 95 so that the downward bearing pressure of the scrubbing uniton the brushes 45 and 46 can be changed by adjusting the valve to changethe size of a bypass orifice and thus change the pressure in the line104 and cause the cylinder 95 to bear more of the weight of thescrubbing unit. It should also be noted that a flow divider 105, whichis shown schematically, divides the flow from the pump 31 so that a lowflow, for example 1 gallon a minute, will be flowing through the valve102. Then, even if the engine drops in r.p.m. so the output of the pumpdrops, this small flow will be maintained, and the cylinder 95 will notsuddenly drop because of a reduction flow through the control valve 102.

A feature of the unit is that the forward housing 108 over the enginehas a center opening 109, that has a sealing member 110 that matesagainst the outer periphery of the inlet opening to the provided enginecooling fan so that there is no possibility for air to be drawn fromaround the interior of the housing 108 into the engine and fresh cleanair will always be blow, across the engine. The engine is a conventionalair cooled engine. The warm air can be disbursed out through suitableducts.

Additionally, the carburetor for the engine can be mounted so that ithas its intake open directly to the air cooling housing for the enginefan so that there is a fresh flow of air coming through opening 109 intothe carburetor which slightly super charges the engine. The engine coverhaving opening 109 of course can be removed for servicing.

A sheet metal housing 107 can be used over the scrubbing unit. Thehousing 107 may also be plastic if desired, and has a movable covermember 107A that is hinged to the main part of the housing 107 and canbe raised and lowered to get into the debris hopper, and remove it forcleaning or to service components in the scrubbing unit. This cover isshown in its dotted position in FIG. 1. The cover 107A when fasteneddown with suitable clamp means, holds the debris hopper in properposition.

FIG. 6 is a hydraulic schematic representation of the drive componentsof the present invention. It was previously mentioned that the unit usedtwo different hydraulic pumps, and'these pumps are shown schematically.The engine 30 drives the hydraulic pump 31 which is the hydraulic pumpfor auxiliary components, and the engine also drives a variabledisplacement piston type pump 29 which is used for driving the wheelmotors 17 and 18 in a closed circuit. The variable displacement pump isa commercially available pump that has a lever control operated by footpedal 21 that regulates the amount of oil that is pumped, and the amountof oil being pumped through the motors l7 and 18, which, as shown, arein parallel, determines the speed of movement of the vehicle. A suitablehydraulic makeup circuit 28 can be installed in this circuit to takecare of any leakage losses and the like. The makeup circuit is a commoncircuit furnished with the pump, which is made and sold by VickersMobile Division of Sperry Rand Corporation. The pump has a swash platecontrol to regulate the amount of fluid under pressure being pumped outinto the motors 17 and 18. The pump is an overcenter pump that mayprovide reverse flow to the motors and thereby reverse rotation of themotors as well as provide a neutral or stopped position.

The second pump for auxiliary components, shown at 31, has the flowdivider 105 built into the pump and this delivers a set low volume, forexample 1 gallon a minute, at a thousand pounds per square inch pressureto the hydraulic cylinder for the control of lifting and lowering thetrailing unit. The valve assembly 102 includes a manually controllablespool shown at 102A that can be shifted from a central position whereinpump from the flow divider will merely pass through the valve and outinto a return line 103 but do this through a variable orifice valve 1028that controls the amount of back pressure in the lines leading from theflow divider 105. A relief valve 102C is also provide across the line torelieve overpressures.

When the valve 102A is shifted to position wherein the side indicated at102D is aligned with line 104, it can be seen that fluid under pressurewill be applied to the hydraulic cylinder 95, but only the amount ofpressure that the adjustable valve 1028 provides as a back pressure.This then actuates the rod 97 of the cylinder at a selected manuallyvariable pressure so that the downward load on the brushes in thescrubbing unit can be regulated by adjusting the valve 1028. When thespool is moved in the opposite direction so that the section 102E alignswith the line 104, the full pressure of the relief valve setting ofvalve 102 can be applied to the cylinder 95, and positively raise thescrubbing unit. This means that the scrubbing unit can thus be held inan upright position, and when the valve spool 102A is again returned toits centered position as shown in solid lines, the line 104 is blockedin the central portion of the valve and the flow from the flow divider105 is directed through the spool into the series circuit through line103.

The cylinder 71 for the rear squeegee assembly 70 is connected through avalve 71A to the line 103. This valve or cylinder 71 is a double actingcylinder and the spool valve 71A is a normal four way valve which willblock both lines leading to the cylinder 71 in its central position, andwill in one position force the rod of cylinder 71 out and in the otherposition force the rod of cylinder 71 in. The unit is normally operatedwith the valve set to force the rod outwardly. A suitable relief valveis also supplied in valve 71A and is set to open when the pressureurging the rod of cylinder 71 out exceeds a preselected amount. Therelief valve setting in valve 71A thus determines the force applied tothe rear squeegee and is usually set very low, for example 50 p.s.1.

The various valves are connected to drain or reservoir through linesshown schematically to the reservoir 33 which is also shownschematically.

The balance of the output of the auxiliary pump 31 comprises a highervolume of flow, for example a flow of seven gallons per minute at ratedspeed for the pump 31. This secondary flow is in a circuit driving thebrushes and the vacuum fan. The flow divider 105 has priority, so evenwhen the motor 31 is running at low speeds the 1 gallon per minute willbe delivered to make the adjustable valve 1028 effective to hold thetrailing unit at the desired force level. This 1 gallon per minute is aconstant flow even though the engine 30 may be idling, so that thesetting of adjustable orifice valve 102B can be held constant.

The pump 31 in a normal situation is used for driving the brush motorsand the fan motor in a series hydraulic circuit. A control valve 113 isused, and in its centered position it will merely return the flow fromthe pump 31 on the secondary side indicated at line 114 to the reservoir33. However, when it is shifted to position so that the section 1 13A isaligned with the center connecting pipes, it can be seen that the branchline 114A will be directed toward a blocked port 114B. The output of thepump 31 on the secondary side is then directed to the motor 51, Then tomotor 52, and then to the motor 75A for the vacuum fan in series. Theother side of the motor 75A then returns to the reservoir. This is thenormal operation where all of the motors are operating at once,including the scrubbing brushes, and the vacuum fan motor.

When the valve 113 is shifted so the portion. 11313 is aligned with thecenter section, it provides a means for stopping the brush motors 51 and52 and operating the vacuum fan motor 75A alone. This may be a situationwhere scrubbing is not desired, but vacuum is wanted, for example, forpicking up of liquid in a stationary position or even picking up liquidwith the squeegees as the unit moves over a surface. In this instance,the

branch line 114 directs the fluid under pressure through a check valve115 into a line 116 that intercepts the series connected line betweenmotor 52 and motor A, and supplies fluid under pressure to this point.Because this pressure will be equal to that on the line 114 through themotors 51 and 52, the motors 51 and 52 will not rotate but will maybestand still, and the entire output of the pump 31 on the secondary sidewill be directed through line 116 to motor 75A and drive this vacuum fanmotor. The valve 113 can again be returned to neutral when the unit ismerely idling and not being used at all. Y

A low pressure bypass valve is used in the return line coming from thevalves 102 and 71A to bypass a filter shown in the return line when thefilter back pressure exceeds this setting.

Thus, the wheel drive circuit is separate from the accessory circuit andthe variable volume pump takes care of just the wheel motors, and thesetting of the pump determines the speed at which the motors operate.The setting of the pump can be actuated through the pedal 21 to operatea swash plate. The pump 29 also drives the unit in reverse.

The accessory pump 31 has a priority circuit through flow divider 105that goes to a cylinder first so that the float on the rear unit can beadjusted accurately by adjusting the variable valve 102B. The unit isthus all hydraulically driven in its accessory and ground drivecircuits.

In operation, the unit is steered through the use of the front steeringwheel. The unit can be moved to scrub within one and a half inches of avertical side wall and will turn corners in a usual manner.

The scrubbing liquid tank has a valve that can be opened so that thescrubbing liquid carries out through openings in the spreader pipe orheader 37, and the hydraulic motors for the scrubbing brushes 45 and 46are activated to rotate the scrubbing brushes 45 and 46 in thedirections as indicated by the arrows for the respective brushes. Thepower unit will then be driven forwardly and debris on the surface 35will be picked up by the leading brush, carried up by the second brushbetween the two brushes together with the scrubbing liquid that hascontacted the surface and a scrubbing action will take place. Scrubliquid is reused by diverting some of the liquid over the front brushand back onto the floor. The frame divider member 43 will divide theflow of liquid and direct the debris backward into the debris hopper. Itshould be noted that the divider frame member 43 is positioned so thatit is closer to the leading brush adjacent the top parts thereof andthis causes debris to be deflected along the trailing surfaces of thisframe member and over the trailing brush back into the rear debrishopper. Liquid will be carried forwardly over the bristles of frontbrush 46 and will be reused or applied to the surface 35 as thescrubbing'action takes place. Liquid collecting onthe divider framemember 43 and along the underside of the plate 42 will drip off the edgeof the frame member back into the forward brush and be carried over thisbrush. Some of the liquid will be carried back by the rear brush 46 intothe debris hopper, which is very close to the brush bristles, and thisliquid will be sucked into the dirty liquid tank through hose connection78A.

Liquid that remains on the surface 35 will be gathered in by thesqueegees as the scrubbing unit moves forwardly and will be trappedbetween the flexible members 74, 74 and sucked by the pipe 78C throughpipe 78B and into the dirty liquid tank as well.

Thus the surface is swept and scrubbed clean and left dry. The scrubbingunit also may be used as a double brush mobile sweeper, merely byturning off the flow of liquid in spreader pipe 37. With the brushesrunning they will pick up dust and debris and deposit it in the debrishopper as the unit moves over the surface. The rear squeegee can beraised and the vacuum can be used for dust control, if desired.

The speed of the scrubbing brushes, the relative size of the twoscrubbing brushes, the spacing between the brushes, and the travel speedof the unit are all interrelated in doing a good scrubbing or sweepingjob. Brush peripheral speeds should be above 1,100 feet per minute.

The use of two brushes traveling at the same speed tends to throw theliquid and debris almost straight up. The deflectors or guides used thendetermine the direction of movement of the liquid and debris. If onebrush rotates faster than the other and both are the same size, thedebris will be deflected at an angle toward the slower brush. If twodifferent size brushes are used, the larger brush deflects the debris atan angle over the smaller brush. Thus, speed and size of the brushes canbe selected to obtain the desired trajectory of liquid and debris whilescrubbing. The brushes are preferably close together, but can be spacedfor debris pick up. The close spacing is helpful for liquid and finedust pick up.

Driving ll 1% inch diameter brushes between 450 and 550 rpm. gives agood balance between ability to pick up dust, dirt, liquid and debrisand prevents atomizing or misting of liquid because of too high a speed,which mainly consumes horsepower. In other words, if the brushes aretraveling at a very high rate of speed, the scrub liquid tends to mist,and the consumption of horsepower goes way up in relation to the abilityto scrub and sweep.

A further point in recirculation of scrubbing liquid is that the guideor divider member 43 is positioned so that the tip of it is above theforward brush in the first form of the invention so that the scrubbingliquid is recirculated. The liquid will drip off the tip of the edgedown on the brush and be recirculated. This is a desirable feature, andof course the positioning of the center baffle therefore is important sothat the tip or edge that extends parallel to the axis of rotation ofthe brush is above the brush bristles and scrub liquid dripping off thistip or edge will be dropped back onto the recirculating brush, which inthis instance is the forward brush 45. If a forwardly mounted unit isutilized, recirculation of liquid can be achieved by having suitablemeans in the debris hopper for recirculating some of the liquid.

In FIG. 7 a modified automatic arrangement for controlling the downpressure on the scrubbing brushes is shown. In this device, the brushes45 and 46 are mounted in the frame as before, and the hydraulic motors51 and 52 are shown mounted to the frame structure 41. In this instance,the hydraulic pump is shown schematically and supplies pressure to thecylinder 95 acting on the link. In this instance, the input line to thecylinder is line 150 connected to a suitable control valve shownschematically at 151, which also controls the flow to the brush drivemotors 51 and 52 through a line 152. As shown, the motors 51 and 52 arehydraulically coupled in series. A cylinder tap off line 153 isconnected to the line between the two motors 51 and 52, and operatesthrough a check valve 154 to connect to the line 150. A small fixedrestriction orifice 154A limits flow into line 150 through the checkvalve. The adjustable flow restriction valve 155 (a variable flow valvewhich is manually operable) is utilized. In normal operation the valve151 is moved to position wherein flow goes from the pump to line 152through motor 51, driving it, and then to motor 52, and then back to thereservoir. The pressure of the motor 52 acts through bleed off line 153causing a flow through check valve 154 and restriction orifice 154A.Flow back to the reservoir through line 150 is restricted to a setamount because of the adjustment of the variable restriction valve 155.The back pressure thus acts on cylinder and acts to exert a liftingforce on the trailing unit.

If the load on the motor 52 increases because of heavier brushing, theincreased pressure in line 153 will act through the check valve 154 toincrease the pressure in line 150 on the base end of the cylinder 95 andthus tend to increase the force bearing on link 88. This will tend tolift the scrubbing unit 12, and will in turn reduce the downward load onthe brushes and consequently reduce the power necessary to drive thebrush motors. A balanced condition will be reached to maintain the loadon the motors 51 and 52 below a maximum. There is therefore an automaticreduction of the load on the brushes when the pressures that operate themotor 52 increases to a point beyond that which the normal pressure inline 150 would be. The check valve 154, of course, prevents flow fromthe line 150 into the motor circuit. In this instance, if the scrubbingunit is to be lifted for transport, the valve 151 can be moved toposition wherein the pump is coupled to line 150. The pressure will thenact to extend the cylinder rod for cylinder 95 and raise the scrubbingunit.

Automatic compensation to prevent killing of the engine 30 is providedbecause the load on the pump shown schematically will be regulated inaccordance with the load on the scrubbing brushes.

Referring to FIGS. 8 and 9, a modified form of the debris hopper isshown. In FIG. 8, the trailing unit 12 is modified so that the frame 41mounts a transverse rear baffle panel that is fixed to the frameadjacent the upper rear parts thereof, and extends downwardly andforwardly and is attached between the side members of the frame. Thebaffle forms a rear wall of the debris hopper indicated generally at 126positioned behind the rear brush 46. The debris hopper includes atransversely extending front panel 127 that is attached between the sidemember of frame 41 and is positioned just immediately to the rear of therear brush 46. Although the vacuum hose is not shown, the vacuum hosewill be used with this hopper as well.

A movable bottom panel 128 is utilized for the hopper, and this is dustsealed along the front and rear edges with respect to the rear panel 125and the front panel 127. The bottom panel 128 is mounted on a centrallymounted rod 129 which is pivotally mounted to a suitable ear 130 on thebottom panel, and also is pivotally mounted to a projecting support 131fixed to the rear panel 125. The link or rod 129 holds the bottom panelin the proper position when the panel is in its solid line position asshown in FIG. 8. The position of the false bottom panel 128 iscontrolled through a pair of spaced apart links 134 that are pivotallymounted to spaced support ears 135 fixed adjacent the front edge of thebottom panel 128 and is also mounted onto the outwardly extending endspaced levers 136 of a bell crank assembly. The levers are fixed to arock shaft 137 that is pivotally mounted to frame members on the rearframe portions of the trailing unit 12. The rock shaft also includes acentral control lever 137A fixed to the rock shaft. The lever 137A isattached as at 138 to the outer end of the rod 139 on a hydraulicpiston-cylinder assembly 140. The base end of the cylinder of thisassembly 140 is mounted as at 141 to 'the frame for the trailing unit12.

The cylinder assembly 140 can be extended and retracted through asuitable control valve 144 that actuates the cylinder from a source ofpressure. When the cylinder is extended, as shown in solid lines in FIG.8, the levers are in their solid line position and the links 134 forcethe false bottom 128 downwardly to close the opening between the frontpanel 127 and rear panel 125. This means that any debris coming from thebrush 46 will be trapped and held in the hopper, and also the scrubbingliquid will be collected and removed with the vacuum line as previouslyexplained.

When the debris hopper fills, however, the false bottom panel 128provides a means for emptying the debris hopper without manually liftingit out as previously shown in FIG. 3A. In order to do this, the valve144 is actuated to retract the cylinder 140 to its retracted positionshown in dotted lines, which will in turn lift the levers as shown indotted lines, and this will cause the bottom panel to pivot about theconnection between the links 129 and brackets 130 and also then willpull up the forward edge of the panel 128 so that the panel 128 willtilt upwardly as shown in dotted lines in FIG. 8. The link 129 will alsopivot about its connection to the supports 131 and will hold the rearedge of the bottom panel downwardly so that the bottom panel 128 extendsalmost substantially perpendicular to the surface being traversedcausing complete dumping of any debris in the hopper, without removingthe hopper itself. The use of the raisable rear squeegee assemblies thusis very important here because the squeegee can be lifted up over thedebris when the scrubbing unit is driven forwardly. This device fordumping also can be used where the main debris receptacle is ahead ofthe brushes, as shown in FIG. 14.

As an alternative, shown in FIGS. 9A and 9B, in place of the hydrauliccylinder 140, a manual lever 145 can be pivotally mounted as at 146 to aportion of the frame for the trailing unit 12 and a link 147 extendsbackward to the trailing unit and is attached at a point 138 to the rockshaft lever. Movement of the manual lever by the operator will cause thesame action as the hydraulic cylinder retracting. This will cause themovable bottom 128 to dump and it can be done manually. This is just analternate method of manual operation as opposed to power actuatedoperation which occurs with the cylinder 140.

clearance when sharp turns are made in either direction with the powerunit 11. This is shown schematically for purposes of illustration, andit is to be understood that the steering and drive mechanism for thepower unit 11 will'be the same as previously disclosed. The mounting forthe scrubbing unit is modified so that the link 88 is replaced with alink that is similar to the link 88 except it has an outwardly extendingend tab 161. In place of the pin and upright channels 87, the trailingunit has a pair of upright posts 162, 162 mounted thereon which arespaced apart a substantial distance and are wider than the link 160. Theupright posts are fixed to the cross frame plate 42 and are sufficientlysturdy and reinforced so that they will support the entire weight of thescrubbing unit 12. A cross shaft 163 is fixedly mounted (it can beremovable if desired) between the posts 162, 162 and extends through thedownwardly depending legs of the bracket 160 as the pin 89 extendsthrough the legs of the bracket 88. However, the shaft 163 is slidablymounted in suitable hubs along the legs of the bracket 160.

The position of the scrubbing unit along the longitudinal axis of theshaft 163 is controlled with a double acting hydraulic cylinder 164 thatis attached as at 165 to the outer end 161 of the link 160, and thecylinder 164 has an extendable and retractable rod 166 that is attachedas at 167 to a bracket that extends upwardly from the base of unit 12 sothat the cylinder is in proper alignment. The cylinder 164 may becontrolled through a suitable valve 168 from a pump and reservoir in theusual manner, and it is a double acting cylinder The links 91 and 92 aspreviously explained, have rod ends at their outer ends where theyattach to the framework of the trailing unit 12 and these rod ends havepart spherical seats of conventional design in the present form of theinvention shown in FIGS. 10 and 10A. The entire scrubbing unit 12 can bemoved axially along shaft 163 by either extending or retracting thecylinder 164. In normal operation the side edge of the trailing unitindicated at 171 is offset from the main part of the vehicle so that itwill travel next to a wall while the power unit is spaced from the wall.In turning away from the wall the cylinder 164 is operated so the edge171 is moved away from the wall so both side edges 170 and 171 of thescrubbing unit are flush with the edges of the power and drive unit. Asharp turn can be made because the scrubbing unit will not immediatelyengage the wall but will give some room for starting the turn before itgets close to the wall. Also, the offset keeps the power unit away fromthe wall for easier maneuvermg.

By properly controlling the cylinder 164, the scrubbing unit can be slidaxially along the shaft 163 to accomplish the desired positioning. Theoffsettable features are desirable whether the scrubber is front or rearmounted. The unit may be operated with the scrubbing unit in its dottedline position with edges 170 and 171 aligned with the edges of the powerunit.

The cylinder 164 may also be automatically actuated by a solenoid valve156 operated by switches 157 actuated by the vehicle steering arm 27after the arm has been moved a preselected amount in either direction.

has wheels, and drivemotors 17 and 18, as well as the steering assemblyarm 27. The motors 17 and 18 are normally in parallel, and both operatein the same direction. A reversing valve 175 is connected to permitnormal parallel operation with both motors turning in the same directionor with one rotating'in reverse from the other. The reversing valve isshown in a reverse position. The valve 175 is controlled by asolenoid176 to its reverse position so motors l7 and 18 rotate in oppositedirections. When the scrubbing machine is to be turned in direction asindicated by the arrow 177, a switch 178 is contacted'by the outer endof the steering arm 27 when the arm reaches its full turn position whichwill energize the solenoid 176 to move the valve 175 to its reverseposition as shown, thus making the machine turn much sharper because ofthe reverse driving actionof the two wheels. Opposite direction reversalis possible by having another switch (not shown) that is engagedby thesteering arm 27 when the wheel for steering is turned in the oppositedirection. By reversing the flow to the wheel motors 17 and 18, thesesharper turns can easily be accomplished. Normally, the motors operatefrom the straight through position of valve 175.

In FIGS. 11, 12 and 13, there is a device shown which is used to directa blast of drying air or gaseous medium onto the surface 35 as shown. Inone form, the engine 30 is an internal combustion engine and the driveshaft is connected throughan engageable-disengageable-(clutched) beltdrive shown schematically at 190 to a centrifugal fan 191 which has apressure outlet 192. This pressure outlet is connected through a pipe193 to a cross pipe 194. The cross pipe 194 has downwardly extendingpipe sections 195 and 196 that are positioned in front of each of thedrive wheels 15 of the power unit. The downwardly extending pipes 195and 196 end in flat broad nozzles 195A and 196A, respectively, that arepositioned closely adjacent surface 35 and immediately ahead of therespective wheel 15 to direct a jet of air down onto the surface andblow any liquid on the surface 35 out of the way, as well as create asurface drying action because of the moving air.

At the forward end of the power unit 12, on the steering member, thepipe 192 is connected to a flexible hose 197. A downwardly extendingpipe 198 then is attached to the mounting frame for the wheel 16, whichsteers and of course moves, so that this downwardly extending pipe 198moves with the wheel. Pipe 198 has a nozzle 198A that is also flattenedout slightly and is directed immediately in front of the steering wheel.The steering wheel 16 is thus also provided with a dry path immediatelyahead of the wheel, even though it may be turned from its straight aheadposition as shown in dotted lines in FIG. 13.

As an alternative and/or supplement, a selector can be used fordirecting heated exhaust gas from the exhaust system of the engine 30into the pipe 192. This is .8 a, shown schematically, and it is to beunderstood that the blower can be disengaged, or left ofi entirely, andonly the exhaust system unit utilized for heated dry air if desired.Likewise, the exhaust system can be left out of the pipe circuitentirely if desired and only the blower 191 utilized.

The exhaust pipe 202 of the engine 30is made so that it normally has anoutwardly extending portion 203 that connects to a suitable muffler ifdesired, or is merely discharged to atmosphere. Between the engine andthe outwardly extending end of the exhaust pipe a selector valveassembly illustrated generally at 204 is provided. The selector valveassembly, as shown perhaps best in FIG. 12, has a flapper valve 205operated by a lever 206 which can pivot about an axis and is movablebetween two positions. A drying gas pipe 207 is connected to pipe 202and also to pipe 192. The flapper valve will move between two positions,one wherein it blocks off exhaust pipe 203 and leaves pipe 207 open, anda second position wherein it blocks off pipe 207 and leaves pipe 203open.

When the use of exhaust gas as a drying medium is desired, for exampleif the heated gas from the exhaust is necessary to provide a drysurface, the belt drive may be disengaged so that the blower is notoperating and the blower blades of course will substantially block theoutlet to the blower 191. This then will permit the moving of the valvelever 206 to its solid line position wherein the flapper 205 blocks offthe pipe 203 and the exhaust gases are forced into the pipe 207 and thenthrough the pipe system 192, 193, 194, 195, 197 and 198. This means thathot air will be blown down onto the surface 35 ahead of the wheelsthrough thenozzles A, 196A and 198A.

If additional air is desired, or a mixing of the air is desired, thebelt drive 190 can be engaged and the blower also utilized. This willcreate some back pressure on the valves of the engine, but the blowerpressure 191 will not. have to be high because of the open pipe systemleading to the nozzles that direct the blasts of air down onto thesurface.

In the usual instance, either the exhaust air or the blower air will beutilized, but in some instances they can be intermixed.

This permits the drying of the surface 35 if it has been previouslywetted by being flooded, or if it is wet prior to the scrubbingoperation.

A feature, of course, is that the scrubber unit, including the spreaderpipe for the scrubbing liquid, whether it be detergent solution orwater, is trailing the drive and steering wheels of the power unit sothat they will normally operate on a dry surface unless the surface 35has previously been flooded or wetted. With the attachments ofthepresent invention, namely the nozzles directing air blasts ahead ofthe drive and steering wheels, the unit can still operate on a drysurface even though it has previously been flooded, and the surface willsubsequently be scrubbed to remove any streaks caused by the drying airand the power unit wheels.

Referring to FIG. 14, a modification of the present invention is shownwherein the scrubber unit can be made with a debris hopper positionedahead of the forward brush in relation to the direction of travel. Thescrubber unit can be made substantially similar as in the previous formof the invention, and the frame 215 is the same as frame 41 inconstruction extending transversely with respect to the direction oftravel, and the frame mounts brushes 216 and 217 for rotation indirection as indicated by the arrows 218 and 219. In this instance,however, the unit is moving in direction as indicated by the arrow 220so that a dirt receptacle or hopper 221 is mounted ahead of the brush217, which in this case would be the leading brush.

The scrubbing unit can either be a trailing unit or a forward pushedunit (which is the form shown) in this instance, and as shown, a mast222 has a link 223 that is a push link attached to a power drive andsteering unit such as unit 12. The push link is pivotally mounted on thepower drive and steering unit and lifted and lowered with a cylindersuch as cylinder 95. Control links 224 to keep the scrubbing unit inproper position are also included. The hopper 221 is constructed withthe dump bottom as described in connection with FIGS. 8 and 9. Thebottom and links are numbered as explained in connection with FIGS. 8and 9. Other types of dumping could be used if desired, or a manuallyremovable receptacle could also be used.

The brushes 216 and 217 are driven by hydraulic motors, and mounted witha removable frame member 225 which corresponds to the frame member 44 inthe previous forms of the invention. The brush mountings would be thesame as before. The brushes would be rotated so that the deflector inthis instance 226 would deflect larger debris forwardly into the hopper221, and a vacuum tube 227 would be used for removing any liquid thatwent into the debris hopper 221.

A secondary debris receptacle 230 is removably mounted just behind therear brush 216 as well, if desired, and as an optional feature this alsowould have a vacuum tube 231 connected to a source of vacuum aspreviously explained to remove any dirty liquid that would get into thedebris receptacle. This receptacle 230 can be smaller than the mainreceptacle which in this instance is positioned ahead of the brushes.

A squeegee assembly 232 corresponding to the rear squeegee assembly 70is also mounted at the rear of the scrubber unit to wipe up any of theexcess liquid, and to remove it with a suitable vacuum hose in the usualmanner.

Thus, it can be seen that the debris receptacle 221 can be positionedahead of or to the rear of the double brush scrubbing unit, and thebaffle 226 can be positioned to give the desireddirection of debristhrow. Further, the brushes 216 and 217 can be run at different speeds,as can the brushes 45 and 46. This will change the trajectory of theswept material.

A scrubbing liquid spreader pipe 233 is mounted on the frame 215adjacent the leading portions ahead of the forward brush 217 when lookedat in relation to the direction of travel, and this liquid spreader pipewill take scrubbing liquid from a scrubbing liquid solution tank on thepower unit used and distribute the liquid onto the surface 234 that isbeing scrubbed.

In FIG. 15, a simplified showing of a scrubbing unit illustratedgenerally at 240 is shown, to show that scrub brushes of different sizescan be used. Here, the frame 241 has a removable debris hopper 242 thatis mounted at the trailing end of the scrubbing unit, and suitable meanscan be used for removing it. As shown, the hopper will lift out of theframe. In this particular instance, the frame 241 mounts a pair ofbrushes, namely a large diameter brush 243, and a smaller diameter brush244 about parallel axes for rotation as indicated by the direction ofarrows 245 and 246. The brushes are driven with hydraulic motors mountedas previously described, and at the idler end of the brushes they aremounted on removable frame member 247 which corresponds to the removablemember previously mentioned. In this instance, a divider guide or baffle248 is mounted to direct debris into the debris hopper 242, and aportion of the scrubbing liquid will be carried over the forward brushand reused. A squeegee assembly is utilized on the trailing end of thescrubber, and on the sides thereof as shown in previous forms of theinvention. In this particular instance, the debris will go over thesmall brush, and the trajectory from the large brush will help to' guidethe debris over as will the deflector or guide member 248. The unit caneither be a trailing or a push unit if desired, using suitable mountingmembers which are not shown to the separate power unit 11. 7

These brushes also usually will be rotating at different speeds. Theoptimum relationship between brush sizes has been found to be 5:4 whichmeans that a 10 inch diameter brush 243 would use an 8 inch diameterbrush 244, and speed ratios is about 2:3 in r.p.m. is found to besatisfactory. For example, if the brush 243, the larger diameter brush,is traveling at 600 r.p.m., the small diameter brush 244 would betraveling at 900 r.p.m. This would make the peripheral speed of thesmall brush greater than the peripheral speed of the large brush, andthis aids in carrying debris over into the hopper. The large brush tendsto throw material upwardly and over the small brush.

The different diameter brushes can be used in the double brush scrubbingunit, and different brush speeds can also be used. The positioning ofthe hopper, whether it be ahead of or trailing the brushes in relationto the direction of movement, is not of critical importance, but in theinstance where a small brush and a large brush are used, the small brushshould be adjacent the hopper lip, as shown at 250. Here'again, thehopper 242 can be removable manually with suitable handles right out ofthe frame 241 and the frame, of course, is constructed as previouslyexplained. The brushes extend transversely across the frame to get thedesired brush width, and the movement of the scrubbing unit can be ineither direction As described, the hopper is trailing. The scrubbingunit will be supported by the power unit 11 and the power unit wouldhold the spreader pipe for applying a scrubbing liquid.

The separate scrubbing unit and power, drive and steering unit areeasily made into a front mounted scrubber. The pull link 88 would becomea push link and the drag links also could be used in compression. Thescrubbing unit could be raised or lowered with a hydraulic cylinder asdesired.

The present device has the ability to operate on smooth or roughsurfaces, as the double brush will clean rough surfaces well.

The solenoid valves used for operating the cylinder 164 for automaticpositioning of the scrubbing unit operate with suitable power sourcessuch as the vehicle battery. Also, the valves are four-way valves andare shown only schematically with pressure sources shown schematically.

1. A surface maintenance device comprising a framework forming ahousing, a pair of rotatable surface engaging maintenance toolsrotatably mounted within said housing about substantially parallelspaced apart axes which are parallel to the surface to be maintained,power means to rotate said maintenance tools when the tools are incontact with said surface, means to apply a liquid scrubbing solution tosaid surface, a receptacle to receive material carried by saidmaintenance tools, and positioned adjacent a first of said tools and onan opposite side of said first tool from the side of said first tooladjacent said second tool, means to determine the path of materialcarried by said maintenance tools to deflect debris from the surfacebeing maintained toward said receptacle and permit a portion of anyliquid picked up by said tools to move in opposite direction from saidreceptacle, said means to determine the path of material comprising aV-shaped deflector forming an edge positioned above and between saidmaintenance tools, and the edge of said V extend-ing downwardly and indirection substantially parallel to the axis of rotation of said surfacemaintenance tools and is positioned above the periphery of the second ofsaid maintenance tools, whereby liquid collecting along said edge anddripping down therefrom under gravity will strike the periphery of saidsecond maintenance tool.
 2. The combination as specified in claim 1wherein said receptacle is removably mounted on said frame for manualmovement thereof.
 3. The combination as specified in claim 1 whereinsaid receptacle has side walls and a movable bottom panel, meansmounting said movable bottom panel with respect to the side wallsthereof, said means mounting said bottom panel permitting movement ofsaid bottom panel from a first receptacle bottom closing position to asecond position wherein said bottom panel is moved to provide an openingthrough the bottom of said receptacle.
 4. The combination as specifiedin claim 3 wherein said means mounting said bottom panel comprisepivoting link means, actuating means for said link means operable tomove said bottom panel substantially 90* between its bottom closingposition and its second position.
 5. The combination as specified inclaim 1 wherein said maintenance tool comprises scrubbing brushes,squeegee means at the trailing end of said unit behind said brushes, andmeans mounting said squeegee means for selective movement toward andaway from the surface to be maintained.
 6. The combination as specifiedin claim 5 and vacuum means to remove material from said receptacle. 7.The combination as specified in claim 5 and a squeegee assembly adjacenteach of the side edges of said surface maintenance unit, said squeegeeassembly including a flexible member, and row brush means attached tosaid flexible member, said row brush means being positioned on each sideof the surface maintenance unit adjacent the rotating brushes andaligned with the transverse gap between the brushes.
 8. The combinationas specified in claim 1 wherein said maintenance tools are brushes ofdifferent diameter.
 9. The combination as specified in claim 1 and meansto rotate said maintenance tools at different rotational speeds.
 10. Asurface maintenance device comprisinG a framework forming a housing, apair of rotatable surface engaging maintenance tools rotatably mountedwithin said housing about substantially parallel spaced apart axes whichare parallel to the surface to be maintained, power means to rotate saidmaintenance tools in opposite direction wherein said tools rotate towardeach other when in contact with said surface, a receptacle to receivematerial carried by said maintenance tools, means to determine the pathof material carried by said maintenance tools to deflect debris from thesurface being maintained toward said receptacle, and permit a portion ofany liquid picked up by said tools to move in opposite direction fromsaid receptacle, said framework comprising a top plate member directlyoverlying and forming a shield over said surface maintenance tools, andsaid means to determine the path of material comprising deflector meansformed as a V-shaped structural member extending transversely along saidtop plate member and fixed thereto to reinforce said top plate member.11. A surface scrubbing machine having a frame member, a pair ofscrubbing brushes rotatably mounted on said frame member aboutsubstantially parallel axes substantially transverse to the direction ofmovement of said scrubbing machine, means to rotate said brushes forscrubbing said surface, means to apply a liquid scrubbing material inthe path of normal travel of said scrubbing brushes, a trash receptacleadjacent one of said brushes, baffle means on said frame member havingsurfaces positioned above and at least partially between said brushes todirect debris over a first one of said brushes toward said receptacle,said surfaces including surface portions inclined downwardly from ahorizontal plane when the brushes are in working position to form anedge at the junction of the surface portions, said edge being positionedto at least be partially above a leading brush in direction of normaltravel of said machine whereby liquid scrubbing material striking saidbaffle will tend to flow toward said edge and drip down toward thesurface.
 12. The combination as specified in claim 11 wherein saidsurface scrubbing machine includes a surface maintenance unit and aseparate power drive and steering unit having drive and steerable wheelmeans thereon, and means to attach said surface maintenance unit to saidseparate power drive and steering unit, said means to attach comprisinga link member, means pivotally mounting said link member to said surfacemaintenance unit, and power lift means for acting on said link member toraise said surface maintenance unit.
 13. The combination as specified inclaim 12 wherein said means pivotally mounting said link member to saidsurface maintenance unit includes means to permit transverse movement ofsaid surface maintenance unit relative to said power drive and steeringunit.
 14. The combination as specified in claim 12 wherein said powerdrive and steering unit has a pair of powered wheels, motor means fordriving each of said wheels under fluid pressure, and means to reversethe direction of said motor means in response to turning to apreselected position with said steering means.
 15. A surface scrubbingmachine having a frame member, a pair of counterrotating scrubbingbrushes rotatably mounted on said frame member about substantiallyparallel axes substantially transverse to the direction of movement ofsaid scrubbing unit, means to apply a liquid scrubbing material in thepath of normal travel of said scrubbing brushes, a trash receptacleadjacent one of said brushes, a baffle on said frame member positionedabove and between said brushes to direct debris over a first one of saidbrushes toward said receptacle, said baffle being positioned so thatliquid hitting said baffle will drip under gravity onto the leadingbrush.
 16. The combination as specified in claim 15 wherein said brusheshave tubular core member, means powering said brushes comprisinghydraulic motors mounted substantially within said tubUlar coresadjacent one end thereof, and idler means rotatably mounting the otherends of brushes.
 17. The combination as specified in claim 16 whereinsaid idler means comprises separate plugs mounted inside said tubularcore members at the opposite ends of said brushes, and bracket meansmounting said idler plugs for removal thereof from said core members ina first direction, said tubular core members being slidably removablefrom said drive motors in direction toward the second ends thereof whensaid bracket means and idler plugs are removed.
 18. The combination asspecified in claim 15 and squeegee means at the trailing end of saidscrubbing machine behind said brushes, and means mounting said squeegeemeans for selective movement toward and away from the surface to bescrubbed.
 19. The scrubbing machine of claim 18 and fluid pressure meansto control movement of said squeegee, control means for said fluidpressure means to limit the amount of downward force on said squeegeemeans.
 20. The scrubbing machine of claim 18 wherein said squeegee meanscomprises a frame, a pair of spaced apart, co-extensive surface engagingflexible member forming a liquid receiving channel, and vacuum means toremove liquid from said channel.
 21. A surface scrubbing machine havinga frame member, means to move said machine along the surface to bescrubbed, a pair of counterrotating scrubbing brushes rotatably mountedon said frame member about substantially parallel axes substantiallytransverse to the direction of movement of said scrubbing machine, meansto apply a liquid scrubbing material in the path of normal travel ofsaid scrubbing brushes, a trash receptacle adjacent a first one of saidbrushes, baffle means to direct solid debris and a first portion of theliquid scrubbing material engaged by said brushes over said first one ofsaid brushes into said receptacle said baffle means on said frame beingpositioned to be more closely spaced from one of said brushes than theother to permit selective separation of liquid and other debris and tocause recirculation of a portion of the liquid scrubbing material pickedup by said brushes back onto the surface being scrubbed in the path oftravel of said brushes.
 22. The surface scrubbing machine of claim 21and a first squeegee assembly, means mounting said squeegee assembly tothe rear of both of said brushes in respect to the direction of travel,said squeegee assembly extending transversely for substantially theaxial length of said brushes, and having forwardly extending portionsadjacent the lateral sides thereof, and separate lateral side squeegeeassemblies adjacent each side of said frame member and to the outside ofthe ends of said brushes, said side squeegee assemblies having trailingend portions overlapping the respective forwardly directing portions ofsaid first squeegee assembly and positioned on the inside of saidforwardly directed portions.
 23. The surface scrubbing machine of claim21 and a squeegee assembly to the rear of said brushes, means to mountsaid squeegee assembly on said frame comprising pivoting parallel armmeans, and means to raise said squeegee assembly off the surface beingscrubbed.
 24. The surface scrubbing machine of claim 21 and vacuum meansto remove liquid from said receptacle.
 25. The surface scrubbing machineof claim 24 wherein said vacuum means includes a vacuum source, a firsthydraulic motor means driving said vacuum source, and a second hydraulicmotor means for driving said brushes, a source of fluid under pressure,and control means controlling operation of said first and secondhydraulic motor means.
 26. The surface scrubbing machine of claim 25wherein said control means permit operation of said first and secondhydraulic motor means simultaneously in series, and selectively permitoperation of only said first motor means.
 27. The scrubbing machine ofclaim 25 and a separate power unit, and a scrubbing unit, means to liftsaid scrubbing unit relative to said power Unit comprising a fluidpressure actuated cylinder, bypass means to control fluid pressure onsaid cylinder said source of fluid under pressure supplying said bypassmeans, and flow divider means from said source of fluid under pressuresupplying a priority flow of fluid under pressure to said bypass means.28. A maintenance machine for surfaces such as a floor or the likecomprising in combination, a maintenance unit comprising a pair ofbrushes rotatably mounted about substantially parallel axes and havingperipheries positioned closely adjacent each other, first power means tomove said unit across a surface to be maintained in direction generallytransverse to the extension of the axes of said brushes, second separatepower means to rotate each of said brushes in opposite directions ofrotation so as to have the brushes rotating toward each other while incontact with the surface to be maintained, said brushes being ofdifferent diameter, a first brush having a smaller diameter, a debrisreceiving receptacle adjacent the side of said first brush opposite fromthe other brush, and in the trajectory path of material engaged by saidbrushes as determined by the different diameter brushes.
 29. Amaintenance machine for surfaces such as a floor or the like comprisingin combination, a maintenance unit comprising a pair of brushesrotatably mounted about substantially parallel axes and havingperipheries positioned closely adjacent each other, first power means tomove said unit across a surface to be maintained in direction generallytransverse to the extension of the axes of said brushes, second separatepower means to rotate each of said brushes in opposite directions ofrotation so as to have the brushes rotating toward each other while incontact with the surface to be maintained, means to rotate said brushesat different speeds of rotation from each other to direct materialpicked up by said brushes from a surface to be maintained at a desiredtrajectory, and a debris receiving receptacle adjacent the side of oneof said brushes opposite from the other brush and in the trajectory pathof material picked up by said brushes.
 30. A maintenance machine forsurfaces such as a floor or the like comprising in combination, amaintenance unit comprising a pair of brushes rotatably mounted aboutsubstantially parallel axes and having peripheries positioned closelyadjacent each other, first power means to move said unit across asurface to be maintained in direction generally transverse to theextension of the axes of said brushes, second separate power means torotate each of said brushes in desired directions of rotation so as tohave the brushes powered for rotation while in contact with the surfaceto be maintained, mechanical means for determining the trajectory ofmaterial picked up by said brushes from a surface to be maintained, adebris receiving receptacle adjacent the side of one of said brushesopposite from the other brush and in the trajectory path of materialengaged by said brushes, said mechanical means comprising a deflectormember having a surface with an elongated axis extending substantiallyparallel to the axes of said brushes, said surface having a dependingedge extending in direction along said brushes, said surface extendingupwardly from said edge and inclined toward said receptacle, said edgebeing positioned closer to said other brush than the distance betweenany portion of said surface and said one brush, whereby said deflectormember deflects larger and lighter particles over said one brush towardthe receptacle.
 31. A surface maintenance device comprising a frameworkforming a housing, a pair of rotatable surface engaging maintenancetools rotatably mounted within said housing about substantially parallelspaced apart axes which are parallel to the surface to be maintained,power means to rotate said maintenance tools when said tools are incontact with said surface, a receptacle to receive material carried bysaid maintenance tools, means to Determine the path of material carriedby said maintenance tools to deflect debris from the surface beingmaintained toward said receptacle, comprising a V-shaped deflectorpositioned above and between said maintenance tools, and an edge surfaceof said V extends downwardly and in direction parallel to the axes ofrotation of said tools, and is positioned above the periphery of one ofsaid tools and permits a portion of any liquid picked up by said toolsto move in opposite direction from said receptacle.